With development of network technologies, Video On Demand (VOD), Internet Protocol Television (IPTV), and videophone have become mainstream services of the broadband network. Such services will also be mainstream services of the 3rd Generation (3G) wireless network.
VOD, IPTV and videophone transmit data like network video. The development of VOD, IPTV and videophone impels the development of network video.
With rapid development of network video, an urgent and important topic in the network video applications is how to evaluate the quality of network video conveniently and effectively. The quality of network videos needs to be monitored to ensure Quality of Service (QoS) of the network videos, and proper measures need to be taken to adjust and maintain the network videos and ensure normal operation of network videos. The quality of network videos depends on diverse factors, for example, QoS (such as bandwidth, packet loss, delay, and jitters) of the transmission channel, and adaptation between the video codec parameter and the transmission channel (such as coding mode, resolution, error-resistivity, and the propriety of the buffer control policy on the codec side). Besides, different locations of the lost video data caused by channel packet loss and delay also affect the subjectively perceived quality of videos in different ways; and the pause or jitter of the video caused by channel delay and jitters also affects the subjectively perceived quality of the video seriously.
In the prior art, a method for detecting the video quality is to calculate a Peak Signal to Noise Ratio (PSNR). The method includes:
obtaining an original reference video and a terminal video;
calculating a PSNR by comparing the original reference video with the terminal video; and
determining quality of the video according to the calculated PSNR.
However, in the prior art:
(1) For a network video, due to limited bandwidth, the obtaining of the original reference video consumes plenty of bandwidth and transmission time, and brings waste of network resources.
(2) The PSNR value reflects only the Signal-to-Noise Ratio (SNR) between the terminal video signal and the original reference video signal. The SNR cannot reflect the users' feeling about the network video played. Therefore, the method of evaluating the video quality in the prior art leads to inaccurate results of detection.